Jack.



No. 742,595. PATENTE'D OCT. 27, 1903.

L. A. GONNER, JL

JACK.

APPLICATION FILED NOV. 3. 1902.

N0 MODEL. 5 SHEETS-SHEET 1.

WITNESSES INVENTOR THE "aims versus co. PHDTO-LITHKI, wnsnmsmn, o c.

No. 742,595. PATENTED 00127, 1903; L. A. comma, JR- JACK- APPLIOATIONFILED NOV. 3. 1902.

5 SHEETS-8111111112.

N0 MODEL.

lrivsu'ron om 0 9 1 7 2 L G 0 D E T ,N E T A P L .J R H. mm 0A .GTU A L5 9. 2 4 7 N APPLICATION FILED NOV. 3. 1902.

v ,5 SHEETS-SHEET 3- H0 MODEL.

INVENTOR WITNESSES N0. 742 ,595. PATBNTBD 001'. '27, 1903.

L. A. CON-NEE, JR;

' JAGK.

APPLICATION FILED NOV. 3. 1902.

w H0 MODEL. 5 SHEETS-SHEET 4.

WIFNESSES INVENTOR L. A. GONNER, JR.-

JACK.

IAPPLIOATION FILED NOV. 3. 1902. no 1101221,,

PATENTED OCT. 27, 1903 5 SHEETS-SHEET 5 parts in lowering position.

inc. 742,595.

I Patented October 27, 1903.

PATENT Fries.

LENDELL A. CONNER, JR., OF PITTSBURG, PENNSYLVANIA.

JACK.

SPECIFICATION forming part of Letters Patent No. 742,595, dated October27 1903. Application filed November 3, 1902. Serial No. 129,871. (Nomodel.)

To all whom it may concern: Y

Be it known that I, LENDELL A. CONNER, Jr., of Pittsburg, Alleghenycounty, Pennsylvania, have invented a new and useful Jack, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawings, forming partof this specification, inwhich- Figure 1 is a sectional side elevation showing a lifting-jackconstructed in accordance with my invention. Figs. 2 and 3 are partialsectional side elevations showing different positions of the partsduring step-by-step lowering. Fig. 4 is a detail view showing anattachment for dropping the bar. Fig. 5 is a broken front elevation ofthe stop-shifting device. Fig. 6 is a rear elevation of the operatingparts, partly in section, at the pivot of the lifting-pawl. Fig. 7 is asectional side elevation of the stop mechanism. Figs. 8, 9, 10, and 11are perspective detail views showing, respectively, the de-tent-pawl,the latch, the latch-pin, and the lifting-pawl. Figs. 12 and 13 aresectional side elevations showing another form of the operatingmechanism with the parts in different positions during lowering. Figs.14 and 15 are detail views of the latch mechanism of this form. Fig. 16is a sectional side elevation showing the invention applied to adouble-toothed bar, the parts being shown in raising position. Fig. 17is'a partial side elevation showing the Fig. 18 is a sectional top planview of the same. Fig. 19 is a diagrammatic side elevation showinganother form with the detent extending upwardly, and Fig. 20 is a detailView of a retarding device which I may employ.

My invention relates to the class of jacks, and is designed to reducethe number of workng parts, to simplify the construction, and

v to make their movements more positive and certain than in previousjacks.

The invention consistsin providing a latch device or prop which ispositively actuated to hold one pawl out of engagement for a certaininterval during lowering, which latch is then tripped to allow the pawlto engage after the bar has been lowered one tooth.

It also consists in providing means where by the movement of the leverpositively retracts the lifting-pawl during lowering, and,

. step lowering.

further, in providing means independent of the casing which positivelymoves such pawl in to engage the tooth, while the other pawl is held outof position during lowering.

The invention further consists in providing mechanism whereby a shortstroke of the lever will lift the bar tooth by tooth, while a longerstroke of the lever will give step-by- It also consists in providing alimiting stop or stops for the lever, which will prevent the longerstroke when lifting, is desired and which is thrown out of action inlowering to allow the longer stroke to be taken.

It also consists in a jack having a single member in addition to thepawls, which single member will act to reverse the movement of thelifting-bar and in such a member which is positively actuated in bothdirections by the movement of the lever.

It further consists in the construction and arrangement of the parts, ashereinafter more fully described and claimed.

In the drawings, referring to the form of Figs. 1 to 10, inclusive, 2represents the easing, 3 the lifting-bar, and 4 the actuatinglever ofthe jack. The head of the lever is pivoted to a pin 5 in the sides ofthe casing and is provided with an inner extension 6, to which alifting-pawl 7 is pivoted by means of a pin 8, having atone end, at oneside of the toothed bar, a projecting cam or lug 9. The pawl 7 isprovided with a downwardly-projecting tailpiece 10, which in thelowering of the rack-bar is adapted to engage a projection 11 on thecasing to throw back thepawl. The other pawl 12, which I have shown asin the form of a detent-pawl, is of U form, is

pivoted below the upper end of the liftingpawl, and is mounted in thecasing in the ordinary manner. This arrangement of the detent-pawl insuch a manner that it engages the teeth at a lower level than theupwardlyprojecting lifting-pawl I believe to be new, and it constitutesan important feature of my invention, as it makes the constructioncompact and simplifies the operating mechanism. One leg of thisdetent-pawl is provided with a projecting-lug 13, having a propping-face14, which is engaged at certain times by a projecting pivoted portion ofthe lever, forming a prop or lat-ch 15. The prop or latch is pivotedabout the pin 5 for the lever-arm, and its hub is provided with anotched or recessed portion 16, within which moves a pin or projection17 on the lever. The end 18 of this prop or latch is of a suitable formto engage the propping-face 14 of the detent-pawl.

In the operation of this jack a short upand-down stroke will lift thetoothed bar step by step in the ordinary manner, and in the movements ofthe lifting-bar the prop, the lug 9, and the stop 11 do not act, sincethe prop is not moved upwardly into propping position. The dotted linesof Fig. 1 show the parts in position when the lever is lifted for takingthe next tooth and lifting the bar, while the full lines show the downposition of the lever after it has been lifted one tooth and thedetent-pawl has swung into the next tooth by gravity. \Vhen it isdesired to lower the bar step by step, the lever is lifted to a greaterextent, and during the latter part of this lifting movement the tail ofthe liftingpawl engages the stop ortail 11, thus throwing thelifting-pawl backwardly into the position indicated ata in Fig. 3, theparts then being in the position shown by the full lines in this figure.As the lever is now lowered its inner end moving upwardly carries thelifting-pawl back into the position indicated by dotted lines at b, andthe face 19of the latch or prop, which is lifted by pin 8, engages thecurved portion 20 of the lug 13. The further movement of the lever thenthrows in the liftingpawl by the cam action of the lug 9 upon the lowerface 21 of the prop, which is at this moment held by the face 20 of thedetentpawl which is supporting the load. The liftingpawl thus beingbrought into engagement with the next tooth, as indicated at c in Fig.3, the further movement of the lever causes the lifting-pawl to take theload and then by the cam action of the portion 19 of the prop upon theface 20 of the detentpawl swings this detent-pawl out of, engagement,and in the last of this down movement the prop is forced into theposition shown in full lines in Fig. 3. ltwill be noted that theswingingout of the detent-pawl and its propping in the out positionoccurs during the last part or excess down movement when the load isagain taken upon the lifting-pawl and is caused by the pin 8 acting uponthe prop. The positive movement of the prop during this action may,however, be obtained by the pin 17 acting upon the lower-part of thenotch at the rear end of the prop, the notch being made shorter. Now onraising the lever to lower the bar the prop will retain its position,holding out the detentpawl until the pin 17 engages the upper shoulderof the notch 16, when the prop will be swung down and the detent-pawlwill swing byits own gravity into the next tooth. It is therefore clearthat a short stroke will lift the bar tooth by tooth, while a longerstroke will lower it tooth by tooth. In order to prevent the longerstroke when it is desired to lift, I preferably provide limiting-stopsfor the lever, which may be drawn out of position to allow the longerstroke to continue in lowering. Thus in this form I show thelimiting-stop as consisting of pins 22 and 23, which are secured to avertically-extending bar 24:, held within recessed pocket in the sideport-ion of the casing. These pins project through in the side of thecasing, as shown at 25, and a third pin 26 is secured to the bar andprojects through an intermediate hole in the casing. The externalportion ofthispinis surrounded by thumbnut 27, having inner cam-faceswhich coact with faces upon the casing. This thumb-nut bears against acollar 28 upon the pin, and by its rotation the stops 22 and 23 aredrawn outwardly against the action of a leaf-spring 29. The thumb-nut ispreferably guarded by a surrounding flange 30, and by turning this nutthe stops may be retracted or-allowed to move into stopping position bythe action of the spring. When the stops are retracted, the movementofthe lever in its longest stroke may be limited by the upper and lowerends of the slot in the casing through which the lever projects. Inorder to provide for aquick drop of the bar, I use a movable pin 17,which is carried by a slide adjustably secured to the lever-head, asshown in Fig. 4. By drawing back the pin when the parts are in positionfor step-by-step'lowering and then depressing the lever the detent-pawlwill be thrown out and remains out, while on the upstroke thelifting-pawl will he forced out, thus entirely releasing the bar. Thesame result can be obtained by a spring-catch to engage the detent-paw],which catch can be set by the operator or by making the pin 8 movableendwise, so that its cam will not engage the lifting-pawl, in which casethe lifting-pawl could remain out and the detent be forced out. In orderto permit the jack to be used at any angle, I provide a device forholding back thelifting-pawlafteritisforced back. This may consistof apin 66, which is pressed forward by a suitable spring 67, attached tothe operating-handle, as shown in Figs. 1, 2, 3, and 20. When the pawlis thrown back during lowering, the catch or retainer will engage theside of the pawl and retain it in the tipped back position until suchpawl is forced forward by the cam action upon it. As the pawl is forcedin the pin 66 is forced back out of engagement with the slightdepression in its side face. During the lifting operation the pin 66 isback of the pawl and out of engagement with it at such times. This catchis applicable to the lifting-pawl in all forms of my device.

In Figs. 12 to 15, inclusive, I show another form of the invention,wherein the cam on the pin of the lifting-pawl is done away with and thepawl is thrown in by a cam-surface upon the detent-pawl and themechanism for changing the movement is altered and simplified. In thisform, in which similar parts are indicated by similar numerals by theICC prime-mark, thedetent-pawl 12"is provided with an extension of thecross-bar portion forming a cam .31, which is arranged to act upon thetail 10 of the lifting-pawl to throw it in after it has been retractedin the lowering movement. In this form instead of forcing the propupwardly by a projecting portion of thepawl-pin I provide a lifting-lug32 on a lever 33, which is pivoted to the pin of the lever. This leveris provided at its rear end with a thumb-piece 34 and has aspringpressed stop 35, which engages a lug 36 on the lever-head when inposition for lowering. In this form in lowering step by step as thelever is raised the tail of the lifting-pawl engages the stop 11 of thecasing, thus retracting the upper pawl into the position shown in fulllines in Fig. 13. is then lowered the cam 31 of the detent-pawl actingupon the moving tail 10 will throw the lifting-pawl inwardly intoengagement with the next tooth above, as shown in dotted lines in Fig.13. On the further down movement of the lever the projection 32 willforce the prop over the cam-face 20 of the detent-pawl and then intopropping position, as shown in Fig. 12. As the lever is now lifted tolower the bar the prop will retain its position until the detent-pawlpasses the point of the next tooth,when the pin 17 will engage thenotched portion of the prop and forceits inner end downwardly, thusreleasing the detent and allowing it to engage the next tooth. When itis desired to lift the bar, the lever 33 is swung to the other sideofthe lug 36, and the projection- 32 will then be inoperative and will notact to move the prop into propping position. A single stationary stop 36maybe used on the casing in this form, which will act during the shortstroke when lifting, but will not act in lowering, owing to the changedposition of the lever 33.

In Figs. 16, 17, and 18 I show the invention as applied to the jackhaving a doubletoothed bar. In this form 37 is the casing, and 38 thebar, having teeth on opposite sides. The lever 39 is provided with aforked head, which embraces the lifting-bar and is pivoted upon oppositepins 40. A liftingpawl 41 of ordinary form is pivoted to the inner sideof the head, while another liftingpawl 42 is pivoted between the outerends of the forked portion, this pawl 42 having a pivot-pin 43, providedwith a projection 44 at one end. This pawl is provided with a tail 45,which in certain positions engages a pin 46, extending between the twosides of the casing. A third detent-pawl 47 of U -shaped form is pivotedto pins 48 in the casing, its legs embracing the forked head of thelever. This detent-pawl engages the teeth on one side below the otherpawls, and one of its legs is provided with a cam portion 49 and apropping-surface 50, adapted to be engaged by a tilting prop 51, pivotedto one of the leverpivots 40. to engage the projection 44 of the lever.42,

As the lever This prop has a nose 52, adapted and a pin 53 on the levermoves within a lower notched portion of this latch or prop. In movingthe lifting-bar upwardly the three pawls are used, thus giving adouble-acting jack with a detent-pawl. In these movements the prop andthe projection 44 perform no function, and the pawl41, abutting againstthe upper end of the casing, limits the upward movement of the lever,while a movable pin 55 limits the downward movement of the lever toprevent forcing out of the detent. When it is desired to give astep-by-step lowering, the lever is moved downwardly a sufficientdistance to enable the pawl 41 to be thrown back through the slot in thecasing to bring it out of action. In this condition the lever is loweredto take the weight upon the pawl 42, and the stop 55 then being pulledsidewise the lever inits further downward movement through the pin 53swings the prop over the cam-face 49 to force out the detent and theninto engagement with the proppingface 50 to hold out the detent. As thelever is now allowed to rise in lowering the load the detent will beheld out until the pin 53 reaches the other end of the notch in theprop, when the prop will be swung back, allowing thedetentto swing bygravity into the next upper tooth. In the further up movement after thedetent has engaged the tail of the pawl 42 will strike the pin 46, thusthrowing back the pawl. movement of the lever the finger 44 will engagethe nose 52, and thus tilt the pawl 42 inwardly into engagement with thenext tooth. In Fig. 17 I show the parts in the position assumed when thedetent is propped out in the last part of the down movement in takingthe load from the lifting-pawl during lowering.

In Fig. 19 I show a formv wherein the detent-pawl 54 projects upwardlyand straddles the lifting-pawl 55 and the lever-head 56. The lower endsof the legs of the detent-pawl are pivoted ,to stub-shafts 57 in thesides of the casing between the lever-pivot 58 and the teeth of the bar59. The one leg of the detent is provided with an inwardly-curvedportion 60 and a shoulder 61, which is engaged by the pin 62 upon thelever to throw in the detent at the proper time in step-bystep lowering,the pin thereafter traveling within the curved face 60. During thislowering the tail 62 of the lifting-pawl 55 engages the pin 63 on thecasing, thus throwing it back in the excess movement asin the otherforms, and as the lever is then depressed this pawl is forced in toengage the next upper tooth by an inclined face 64 on the detent, whichis then holdingthe load. As the depression of the lever continues a pin65 on the lever-head forces back the detent-pawl, so that it falls intothe position shown in full lines. It retains this position by gravityuntil the load is lowered by allowing the lever to rise to such a pointthat the pin 62 engages shoulder 61 and throws in the detent to engagethe next tooth, and after this on the further depression of the leverthe lifting-pawl is again thrown out. The limiting-stops to prevent theexcess movement in raising may be used as in the first form.

By excess movement I mean the continued movement of the lever after theload has been taken by one of the pawls.

The advantages of my invention will be apparent to those skilled in thisart. The parts are simple, few in number, and maybe easily and cheaplymade and assembled. Only one piece is used besides the pawls inreversing the movement, this piece being in the nature of a prop, whichis positively moved into propping position by the lever and is thenforced out of this position by the lever to release the pawl at theproper time. The movements of the lifting-pawl are under positivecontrol during lowering, it being moved back and forced in by themovements of the lever. The lowering action is not dependent upon theaction of a weight or spring, and the only gravity movement is that ofthe detentpawl when it is released. The amount of throw of the pawls iseasily regulated and changed by changing the shape of the camsurfaces.The movement of the bar may be reversed either by changing movable stopswhich limit the movement of the lever or by shifting the means formoving the prop into propping position, and in the first case themovement is reversed by merely changing from a long to a short stroke.The position of the detent-pawl is of advantage, as it makes themechanism compact and brings the pawl into position where the propdevice may act upon it directly without complicated connections. Thesystem is easily adaptable to single or double toothed jacks ofdifierent varieties and is not liable to get out of order.

Many variations may be made in the form and arrangement of the pawls,their connections, the prop device, and method of operating it, as wellas in the general form of the jack and lever, without departing from myinvention.

I claim- 1. A jack having a toothed bar and a plurality of pawls, alever, and mechanism actuated by the lever and arranged to force outboth of said pawls positively and successively during the step-by-steplowering; substantially as described.

2. A jack having a plurality of pawls, apivoted prop device swingingabout a fixed center with respect to the lever and arranged to act uponone of the pawls, and mechanism actuatedby the lever for moving the propinto and out of operative position during step-bystep lowering;substantially as described.

3. Ajack havingaplurality of pawls, a prop device swinging about a fixedcenter with respect to the lever and arranged to act upon one of thepawls, and mechanism for positively moving the prop into and out ofoperative position during lowering, said prop being inoperative duringraising, substantially as described.

4. A jack having a plurality of pawls, one of which is a detent-pawl, aprop device swinging about a fixed center with respect to the lever andarranged to act upon said detentpawl, and mechanism for positivelymoving the prop device into and out of operative position duringstep-by-step lowering; substantially as described.-

5. A jack having a toothed bar, and a plurality of pawls, a lever,mechanism actuated by the leverand arranged to force out both of saidpawls positively and successively during step-by-step lowering, a proparranged to hold out one of said pawls, and mechanism for setting andtripping the said prop; substantially as described.

6. A jack having alifting-pawl mounted on the lever, a device actuatedby the lever and arranged to force said pawl outwardly, a catch arrangedto retain the pawl in retracted position, and means for then forcing thepawl inwardly, said parts being adapted to act during step-by-steplowering; substantially as described.

7. A jack having a toothed bar, a plurality 5 of pawls, a lever, and asingle element acted upon directly by the lever and arranged to actdirectly upon a pawl to force it out during step-by-step lowering;substantially as described. I00

8. A jack having a plurality of pawls, one of which is a detent-pawlhaving a projecting tailpiece, and a detent or prop device arranged toact upon the tailpiece during the step-by-step lowering; substantiallyas described.

9. A jack having a plurality of pawls, one of which is a detent-pawlhaving a tail portion with a cam-surface thereon, and a member actuatedby the lever and arranged to act 1 10 upon the cam-surface and move thedetent outwardly in step-by-step lowering; substantially as described.

10. A jack having a toothed bar, a plurality of pawls, a lever, and asingle propping elen5 ment arranged to act directly upon a pawl, to propand hold it out of engagement during step-by-step lowering, saidpropping element being actuated directly by the lever; substantially asdescribed.

11. A jack having a toothed bar, a plurality of pawls at least one ofwhich has a projecting tailpiece, a lever, and a device arranged to actupon a pawl arm or tail to force said pawl out of engagement with theteeth during stepby-step lowering; substantially as described.

12. A jack having a toothed bar, a lever, a lifting-pawl anddetent-pawl, and an actuating connection with the lever arranged to 1 0positively force the lifting-pawl into engagement with the teeth by camaction of a moving element, during step-by-step lowering; substantiallyas described.

13. A jack having a lifting-pawl mounted on the lever, an abutment onthe casing arranged to contact with and force out said pawl during thelever movement, and mechanism for moving in said pawl, duringstepby-step lowering; Substantially as described.

14:. A jack having a detent-pawl, a liftingpawl mounted on the lever,and mechanism connected to the lever and arranged to force thelifting-pawl outwardly and inwardly during the step-by-step lowering;substantially as described.

15. A jack having a toothed bar, a plurality of pawls, a lever, a propdevice arranged to hold out one of the pawls during step-by-steplowering, connections arranged to trip the prop, mechanism for throwingthe tripping device out of action, and mechanism for forcing out theother pawl to give a full drop; substantially as described.

16. A jack having a lifting-pawl and a stop or abutment arranged toforce the pawl out by cam action in the last part of each loweringmovement; substantially as described.

17. A jack having a plurality of pawls, one of the pawls being alifting-pawl, a stop or abutment arranged to force the lifting-pawl out,and mechanism independent of the casing for then forcing said pawl in bya cam action, during the step-by-step lowering; substantially asdescribed.

18. A jack having a prop device arranged to act upon a pawl duringstep-by-step lowering, a stop arranged to prevent action of the propduring step-by-step lifting, and mechanism for preventing the action ofthe stop during step-by-step lowering; substantially as described.

19. A jack having a detent-pawl and a lifting-pawl, a prop devicearranged to act on the detent-pawl during step-by-step lowering, a stoparranged to prevent the action of the prop during step-by-step lifting,and mechanism for preventing the action of the stop during step-by-steploweringysubsiantially as described.

20. A jack having a detent-pawl and a lifting-pawl, and a prop deviceconsisting of a single pivoted element actuated directly by a leverextension and arranged to act upon the detent-pawl to producestep'by-step lowering, substantially as described.

21. A jack havingatoothed bar, aplurality of pawls, an operating-lever,a device actuated by the movement of the lever having the same center ofmotion as that of the lever, said device being arranged to force one ofsaid pawls out of engagement with the toothed bar duringstep-by-steplowering, and a tripping device arranged to permit said pawlto take the load; substantially as described.

22. A jack having a detent-pawl, and a lifting-pawl mounted on thelever, a pivoted prop arranged to force the detent out and then allow itto swing in during step-by-step lowering, lever connections arranged toactuate said prop positivelyin both directions,

and mechanism for forcing the lifting-pawl outwardly and then moving itinwardly during step-by-step lowering; substantially as described.

23. A jack havinga rack-bar,a detent-pawl,

alifting-pawl mounted on the actuating-lever,,

a pivoted prop device coacting with the detent-pawl and actuated bylost-motion connection with the lever, a cam device arranged to throwout the lifting-pawl during the excess upward movement of the outerlonger arm of the lever, a cam device arranged to throw in thelifting-pawl during the downward movement of the longer arm of the leverand mechanism for releasing the prop during the downward movement of therackbar; substantially as described.

24. A jack having a rack-bar,a detent-pawl, alifting-pawl mounted on theactuating-lever, a pivoted prop device coacting with the detent-pawl andactuated by lost-motion connection with the lever, a cam device arrangedto throw out the lifting-pawl during the excess upward movement of thelong arm of the lever, a cam device arranged to throw in thelifting-pawl during the downward movement of the long arm of the lever,mechanism for releasing the prop during the downward movement of therack bar, a stop device, and mechanism for preventing the action of thestop device during lowering; substantially as described.

25. A jack having lifting and detent pawls, an operating-lever, a singleprojecting portion or element carried by said lever and arranged todirectly engage the detent-pawl and disengage the same from the rackduring stepby-step lowering; substantially as described.

26. A jack having a toothed bar, a plurality of pawls, anoperating-lever, a projecting element or prop pivoted on the same axisas the lever and arranged to act on the detent-pawl during step-by-steplowering, said prop being inoperative during lifting; substantially asdescribed.

27. A jack having lifting and detent pawls, an operating-lever, aprojecting portion carried on the lever and arranged to directly engagethe detent-pawl in step-by-step lowering, mechanism for retracting theliftingpawl during the step-by-step lowering, and a device for holdingback the lifting-pawl until forced in the next tooth; substantially asdescribed.

28. A jack having a toothed bar, a plurality of pawls and mechanism forreversing the .movement of the bar, said mechanism being actuated by thelever in its excess movement over that of moving the bar in onedirection, and having a fixed relation to theactuatinglever;.substantially as described.

29. A jack having a toothed bar, a plurality of pawls, mechanismarranged to move out one of said pawls at a predetermined point in theexcess movement of the lever after the other pawl has taken the load instep-by-step lowering, and a stop arranged to prevent the lever fromreachingsaid predetermined point; substantially as described.

30. A jack having a toothed bar, and a plurality of pawls, mechanismhaving actuating connection with the lever and arranged to move out oneof said pawls at a predetermined point in the excess movement of thelever after the other pawl has taken the load in step-by-step lowering,and a stop arranged to prevent the lever from reaching saidpredetermined point; substantially as described.

31. A jack having a toothed bar, a plurality of pawls, mechanismarranged to move out each of said pawls at a predetermined point in theexcess movement of the lever after the other pawl has taken the load,and movable stops arranged to prevent the le verfrom reaching saidpredetermined points; substantially as described.

32. A jack having a toothed bar, a plurality of pawls, a lever arrangedto actuate at least one of said pawls in lifting the load, and mechanismarranged to remain in the same position during movement of the bar ineither direction, said mechanism having connections with the leverarranged to force out one of said pawls at a predetermined point in theexcess movement of the lever after the load has been taken on the otherpawl in step-bystep lowering; substantially as described.

In testimony whereof I have hereunto set my hand.

L. A. CONNER, JR.

Witnesses:

GEO. B. BLEMING, WARREN W. SWARTZ.

